India ink preparation of CSF from a patient with chronic meningitis reveals budding yeast cells surrounded by clear unstained halos. The halo represents:

• A A shrinkage artifact around the cell wall
• B A true capsule that excludes the ink particles ✓
• C A zone of hemolysis around each yeast cell
• D Depolymerized peptidoglycan at the cell surface

Explanation

India ink is a negative stain: colloidal carbon particles cannot penetrate the polysaccharide capsule of Cryptococcus neoformans, so the capsule appears as a clear halo against the dark background. It is a genuine anatomical structure, not artifact, and its demonstration in CSF supports a rapid presumptive diagnosis of cryptococcal meningitis.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.